This invention relates to exercise machines and more particularly to a machine for strengthening the hand grip that employes variable captive weights.
Exercisers manufactured exclusively for strengthening the gripping muscles of the hand, as exemplified by U.S. Pat. Nos. 1,495,278 and 689,652 generally employ a spring biasing force aganist which the gripping hand acts. Exercising machines employing an adjustable variable stack of weights to be lifted, as exemplified by U.S. Pat. Nos. 4,456,245; 4,627,615: 4,577,861 and 4,606,540, have the advantage of precise forces against which the muscles must act, however they have general exercise utility and are not designed specifically for the special function of hand grip exercising. Consequently, they cannot perform this function in an optimal manner.
The prior art device shown in FIG. 1 has been used for grip exercising with a spindle 1 upon which removable bar bell disc weights 2 of various sizes may be mounted. The carriage 3 lifts the spindle 1 and the mounted weights 2 when the movable handle 4 attached to carriage 3 is pulled upward toward the stationary handle 5 by gripping motion of the hand. This device has the economic advantage of not requiring its own set of weights. However, it has the disadvantage of requiring the lifting on and off of weights to adjust resistance. The device is not suitable for a health club application wherein multiple users may misplace weights. Furthermore, its structure interferes with comfortable use.